Untersuchungen an auf InP basierenden Halbleitern mit sub-ps Responsezeiten

by Biermann, Klaus

Abstract (Summary)
The present work describes investigation of new material concepts accomplished using molecular-beam-epitaxy (MBE) growth for application in ultra-fast photonic components. Nominally undoped and Be doped GaInAs/AlInAs multiple-quantumwell structures (MQW) were grown by MBE at growth temperatures down to 100 °C (LT-MBE) on semi-insulating InP substrates. Crystalline, electric and optical properties of as-grown and annealed structures were investigated. Energy states near the conduction band of GaInAs determine the electrical and optical properties of LT-MQWs. The dynamics of charge carrier relaxation was studied by means of pump and probe experiments. Measurements of the differential transmission when excited by an additional cw laser and measurements utilizing two closely sequenced pump pulses support the capability of Be doped as-grown (annealed) LT GaInAs/AlInAs MQW structures for use in optical switches at switching frequencies in the 1 Tbit/s (250 Gbit/s) range. The voltage-induced change of interband transmission of InP based quantum-cascade-lasers (QCL) during pulsed mode operation was analyzed by means of 8 band k*p calculations. The impacts of varying charge carrier distributions and of electrically heated samples can be neglected compared to the dominating effect of the electrical field on the interband transmission. The impact of MBE growth parameters on the interface quality of AlAsSb/ GaInAs heterostructures were determined by means of Hall measurements, temperature- and intensity-dependent PL measurements and spectral measurements of the interband- and intersubband-absorption. The impact of In segregation and Sb diffusion on the intersubband absorption was analyzed on the basis of bandstructure calculations. Intersubband transitions at wavelengths of about 1800 nm (1550 nm) were successfully achieved in MQW (coupled QW) structures.
This document abstract is also available in German.
Bibliographical Information:


School:Humboldt-Universität zu Berlin

School Location:Germany

Source Type:Master's Thesis

Keywords:LT GaInAs/AlInAs MQWs Kurzzeitspektroskopie Quantenkaskadenlaser Ultrafast Spectroscopy Quantum-Cascade-Laser Short Wavelength Intersubband Transitions


Date of Publication:07/23/2007

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